The present invention is related generally to medical devices. More specifically, the present invention relates to face masks which can find one use in delivery of anesthesia and respiratory gases. The present invention includes a standard breathing circuit port and a variable inside diameter port which can be used to form an airtight seal about fiberoptic laryngoscopes and endotracheal tubes.
The use of endotracheal tubes or breathing tubes is the preferred and standard method for administering general anesthesia for major surgical procedures. The endotracheal tube typically has a distal end carrying an inflatable balloon disposed about the circumference. The balloon can be inflated to form an air tight seal within the trachea once the endotracheal tube distal end is in place. The proximal end of the endotracheal tube typically has a standard connector, having nominally xe2x85x9cth inch inside diameter and ⅝th inch outside diameter. The endotracheal tube may be put into position by an anesthesiologist, the distal balloon inflated, and the oxygen and anesthesia gases delivered to the patient. The endotracheal tube is typically put into position after the patient has been put under, to avoid patient gagging on the inserted endotracheal tube.
Some patients present xe2x80x9cdifficult airway situations.xe2x80x9d These situations make it difficult to place the endotracheal tube. Examples of difficult airway situations include patients having short muscular necks, receding lower jaws with obtuse mandibular angle, limited cervical spine mobility, and poor mobility of the mandible. Extremely obese patients may also present a difficult airway situation. In a difficult airway situation, an anesthesiologist may be forced to use a flexible fiberoptic scope to identify or locate the proper position for the endotracheal tube, followed by coaxially sliding the endotracheal tube over the pre-positioned fiber optic tube.
One exemplary scenario illustrates one set of problems addressed by the present invention. A patient is wheeled into an emergency room, in critical condition, having been involved in an automobile accident. The patient has significant internal injuries with internal bleeding, requiring immediate surgery. The patient""s neck has been fractured in the accident, and significant movement of the neck may render the patient quadriplegic for the remainder of their life.
If the anesthesiologist tilts the head backward to insert the breathing tube to begin general anesthesia, the patient may be rendered paraplegic. If the anesthesiologist does not insert the breathing tube, general anesthesia, and therefore surgery, cannot be begun. One solution is to perform a tracheotomy. This can include cutting the patient""s neck and inserting an endotracheal tube through the front of the neck. While the patient""s skin may be numb, the cutting will generally be performed prior to the administration of general anesthesia, while the patient is awake. This is a less than optimal situation for the still awake, and injured patient.
One method to address the above situation includes inserting a fiberoptic laryngoscope to identify the trachea, followed by the insertion of the endotracheal tube over the laryngoscope. If the fiberoptic laryngoscope were inserted with no sedation or general anesthesia, the patient""s gag reflex and general panic may result in the patient gagging, biting through the fiberoptic laryngoscope, and even vomiting, with the possible aspiration or inhalation of vomit and resultant suffocation. All this is occurring prior to proper placement of the endotracheal tube, before the required major medical procedure has even begun.
In order to deal with the above mentioned problems, the anesthesiologist may be required to sedate the patient simply to insert the fiberoptic tube and/or endotracheal tube. When the patient is sedated, the reaction of the patient may be highly variable and unpredictable. A dose of a sedative, for example, sodium pentathol, may leave one patient awake and thrashing, while causing the complete cessation of breathing in another patient. If too low a dose is initially given, the time elapsed before placement of the breathing tube and the initiation of surgery is increased. If too high a dose of sedative is given to the patient, breathing will stop, with death eminent unless positive pressure ventilation can be begun. Positive pressure ventilation through the endotracheal tube could be initiated if the endotracheal tube were in place. Unfortunately for the patient, that is not the case.
The anesthesiologist facing this difficult situation may thus be faced with a patient thrashing about while the fiberoptic probe is inserted into his trachea, or faced with the situation where the patient has ceased breathing and has no endotracheal tube yet in place.
General anesthesia gases may be delivered through a standard, soft sealing face mask. However, this standard face mask must be removed in order to insert the fiberoptic laryngoscope, thereby ceasing delivery of the anesthesia gas. If the patient has ceased breathing due to the sedative previously administered, a standard face mask may be used to provide positive pressure ventilation, forcing enriched oxygen gases into the patient""s lungs. However, when the standard face mask is removed, the patient no longer breathes, and the blood oxygen level drops or desaturates, along with any delivered general anesthesia gas. Once the standard face mask is removed, the anesthesiologist is under intense time pressure to properly position the fiberoptic laryngoscope and the endotracheal tube. The time required to properly place the fiberoptic laryngoscope and the endotracheal tube is time in which the patient is not receiving any general anesthesia gas and is not receiving any oxygen. If the procedure is too difficult and requires too much time, the patient may awaken due to lack of anesthesia gases and/or approach death due to lack of oxygen.
What would be desirable is a sealing face mask which permits simultaneous positive pressure ventilation, delivery of anesthesia gases, and also allows simultaneous placement of medical shafts such as fiberoptic probes and endotracheal tubes, together with maintenance of positive pressure and delivery of oxygen to the patient. What would be advantageous is a face mask which permitted simultaneous introduction of numerous diagnostic and therapeutic devices into the mouth and nose of a patient concurrent with the delivery of positive pressure ventilation.
The present invention provides intubating ventilatory face mask apparatus and methods. One face mask includes a central region surrounded by a peripheral soft seal region. A breathing circuit port can be disposed on the mask as well as an instrument port. The instrument port can have a controllably variable or adjustable inside diameter. The instrument port inside diameter can be controlled through the increase and decrease of the inside diameter of the sealing wall of an instrument cuff or envelope disposed within the instrument port. In one mask, an inflatable envelope or balloon material is disposed within a short, tubular, instrument port lip or wall. The cuff can be inflated and deflated through an attached valve or port. One mask is adapted to receive a standard syringe to inflate and deflate the instrument port cuff. A snap fit lid can be provided for sealing the instrument port when its use is not required. The inside diameter of the instrument port is preferably adjustable between a size small enough to form an air tight seal about a fiber optic laryngoscope, and a size large enough to allow passage of the proximal connector of an endotracheal tube. In one embodiment, the inside diameter of the instrument port is controlled through an iris mechanism, analogous to that found in camera lenses.
One mask has an internal volume of between about 100 and 150 cubic centimeters. The instrument port is preferably centrally located with respect to the apex of the mask conical area or dome. The standard breathing circuit port is preferably located off-center, being located further off-center relative to the instrument port. The centrally disposed instrument port can better provide access to the nose and mouth.
The present invention includes a method for providing a breathable gas to a patient. One method includes providing a mask having a first aperture and a second aperture, with the first aperture having a controllably variable or adjustable inside diameter. The second aperture can be in fluid communication with the breathable gas. The method includes placing the mask on the face of the patient, and can include forming an airtight seal between the face and the mask. The method further includes supplying the breathable gas to the patient through the second aperture, and inserting a first shaft member through the first aperture. The first aperture can be closed about the inserted first shaft member, with airtight seal being formed in some methods between the shaft and first aperture walls. The first shaft member can be advanced into the mouth, nose, trachea, or esophagus of the patient, while supplying the breathable gas to the patient.
In some methods, the supplying step includes supplying the breathable gas at a positive pressure to the patient between the face and mask. The breathable gas can be enriched in oxygen and may include anesthetic gases. In some methods, the first shaft member is a fiber optic laryngoscope and the method further includes identifying or locating the trachea. The method may include providing a second shaft member having a lumen at least partially therethrough, and advancing the second shaft lumen over the first shaft, through the mask first aperture and into the patient. The method may further include the second shaft being an endotracheal tube, the method further including supplying the breathable gas through the breathing tube and removing the mask from the face region of the patient over the endotracheal tube. The mask may be removed over the endotracheal tube even where the endotracheal tube has a proximal connector and the proximal connector is passed through the variable sized first aperture.
The present invention may be used in difficult airway situations, where it is desirable to place a breathing tube into the trachea of a patient, and where a fiber optic laryngoscope is preferably used to identify the trachea, followed by advancing an endotracheal tube over the positioned fiber optic laryngoscope. The mask may be positioned over the face of a patient, and positive pressure ventilation and delivery of general anesthesia gas begun immediately. A fiber optic laryngoscope may be advanced through the first, adjustable inside diameter aperture while maintaining an airtight seal between the fiber optic laryngoscope and the adjustable inside diameter aperture.
With the trachea identified, the endotracheal tube may be passed over the prepositioned fiber optic laryngoscope, and the adjustable inside diameter of the first aperture increased to allow passage of the endotracheal tube, while maintaining an airtight seal between the endotracheal tube outer wall and the inner wall of the first aperture. The endotracheal tube can be positioned within the trachea, and the fiber optic laryngoscope removed, all while maintaining positive pressure and delivery of breathable gas to the patient. With the endotracheal tube in place, the mask controllably variable sized first aperture may be dilated, for example, by evacuating the gas from an inflatable cuff. With the inside diameter of the first aperture increased, the mask may be removed over the proximal end of the endotracheal tube. The breathing circuit may be then coupled directly to the proximal connector of the breathing tube, and breathable gases delivered through the endotracheal or breathing tube.
In some exemplary and non-limiting uses of the invention, the mask may be used in procedures including the examination and treatment of lesions of the nose, sinuses, mouth, larynx, pharynx, trachea, bronchi, esophagus and stomach. In one beneficial use of the present invention, the mask may be carried in an ambulance, and applied to the face of an accident victim, with the variable sized first aperture initially covered with a lid. A breathable gas may be delivered through the second aperture. If it is necessary to introduce a breathing tube, the lid may be removed, the inside diameter of the first aperture increased or decreased, and the fiber optic laryngoscope and/or breathing tube inserted through an airtight seal formed between the inserted shaft and the variable inside diameter aperture. The positive pressure provided by the mask and the breathable gas delivered through the mask need only be momentarily discontinued when the mask is lifted free of the positioned breathing tube. The same mask may thus remain in position from the initial placement in the ambulance until the breathing tube has been successfully positioned within a hospital.